IRON TRANSPORTER-FUNCTIONAL CHARACTERIZATION--REGULATION

铁是所有物种必需的微量元素。它是利用 它是许多蛋白质中的重要辅因子。 然而，如果它积累过量，它可以催化 形成危险的有机和氧基有毒自由基。 因此，该游离过渡金属在 生物液体受到严格控制。在肠道中， 还原剂，如抗坏血酸，以及活性 铁还原酶增强铁的吸收，使铁 通过Fe 2+特异性转运系统转运到肠上皮细胞中。 尽管有广泛的研究，肠铁的分子机制， 吸收仍然是未知的，Fe 2+转运蛋白尚未被发现。 报告哺乳动物。在Hediger博士的实验室工作（我的 最近，我成功地克隆了一个Fe 2 + 转运蛋白（IDCT 1，铁偏好二价阳离子转运蛋白1） 用爪蟾表达克隆法从缺铁大鼠十二指肠中获得铁蛋白 卵母细胞本提案的目标是描述这一点， l）阐明结构-功能 IDCT的关系1，2）确定细胞和亚细胞 使用免疫细胞化学在各种组织中定位IDCT 1， （3）研究IDCTI mRNA的调控。我也是 建议克隆一个假定的低亲和力铁转运蛋白， 就像锌一样。

Iron is an essential trace element for all species. It is utilized by all cells and represents an important cofactor in many proteins. Yet, if it accumulates in excessive amounts, it can catalyze the formation of dangerous organic and oxygen-based toxic radicals. Therefore, the concentration of this free transition metal in biological fluids is under tight control. In the intestine, reductants such as ascorbic acid, as well as the activity of ferrireductase enhance iron absorption, allowing iron to be transported into enterocytes via a Fe2+-specific transport system. Despite extensive studies, molecular mechanisms of intestinal iron absorption remain unknown, and an Fe2+ transporter has not yet been reported for mammals. Working in the laboratory of Dr. Hediger (my sponsor), I have recently been successful in cloning an Fe2+ transporter (IDCTl, Iron preferring Divalent Cation Transporter l) from iron deficient rat duodenum by expression cloning with Xenopus oocytes. The goal of this proposal is to characterize this transporter protein by l) elucidating the structure-function relationship of IDCTl, 2) determining the cellular and subcellular localization of IDCTl in various tissues using immunocytochemistry, and 3) investigating the regulation of IDCTI mRNA. I am also proposing to clone a putative low affinity iron transporter, as well as a zinc.